opinion: ivjlr. justice PKANJKr unjin
  delivered the opinion of the Court.
  In April 1955 Charles A. DePriest began an action in the District Court for the District of New Jersey, claiming $27,000 in additional compensation from the Pennsylvania Railroad. DePriest .had been employed as a locomotive engineer by the Railroad from May 1918 to March 1955, at which time he resigned his employment and applied for an annuity. He alleged that under the terms of a collective bargaining agreement between the Railroad and Brotherhood of Locomotive Engineers of which he was a member, he was entitled to an extra day’s pay for each of the 1,000-1,500-times he had been assigned to leave his switching limits and perform service for his employer on tracks belonging to the Baltimore and Ohio Railroad Co. He relied on a provision of the collective bargaining agreement 'which provided extra compensation for engineers who'were used beyond their switching limits under specially defined circumstances. DePriest further alleged that his claim had been rejected by his employer’s representatives, including the Railroad’s chief operating officer for the region in which he was employed. His retirement from service occurred immediately after this alleged rejection. Jurisdiction was based on diversity of citizenship... The District Court stayed the proceedings awaiting the disposition of similar claims against the Pennsylvania Railroad then pending before the First Division of the National Railroad Adjustment Board, 145 F. Supp. 596. An appeal from this interlocutory decision, not one granting or denying an injunction, was dismissed. 243 F. 2d 485. In the interim DePriest died and was replaced by an administrator. Following a rejection by the National Railroad Adjustment Board of claims against the Pennsylvania Railroad involving the same provisions of the collective bargaining agreement, the District Court dismissed the complaint on the ground that the Board’s' interpretations were final and as such binding on respondent, 155 F. Supp. 695. The Court of Appeals reversed, 258 F. '2d 62, holding that the determination by the Board of claims to which respondent was not a party was n'tet binding on him, and that the District Court had jurisdiction over the claim. We granted certiorari, 358 U. S. 878, since- this decision raised an important question in the administration of the Railway Labor Act of 1934. That Act, 48 Stat. 1185, 45 U. S. C. § 151 et seq., established a broad framework, for the regula^ tion and adjustment of industrial controversies involving railroads.
  The Act establishes, inter alia, the National Railroad , Adjustment Board with the following purposes and functions:
  “The disputes between an employee or group of employees and a carrier or carriers growing out of grievances or out of the interpretation or application of agreements-concerning rates of pay, rules, or working conditions, including cases pending and unadjusted on the date of approval of this Act, shall be handled in the usual manner up to and including the chief operating officer of the carrier designated to handle such disputes; but, failing to reach an adjustment in this manner, the disputes may be referred by petition of the parties or by either party to the appropriate division of the Adjustment Board with a full statement of the facts and all supporting data bearing upon the. disputes.” Railway Labor Act, § 3, First (i), 45 U. S. C. § 153, First (i).
  The clash of economic forces which led to the passage of this Act, the history of its enactment, and the legislative policies which it expresses and which guide judicial interpretation have been too thoroughly and recently canvassed by this Court to need repetition. On the basis of these guides to judicial construction we have held that the National Railroad Adjustment Board had exclusive primary jurisdiction over disputes between unions and carriers based on the provisions of a collective bargaining agreement. Slocum v. Delaware, L. & W. R. Co., 339 U. S. 239. On the same day, we also decided Order of Railway Conductors v. Southern R. Co., 339 U. S. 255, holding that the principles of Slocum were fully applicable to a claim by a group of conductors that they were entitled to extra compensation for certain “side trips” under the terms of their agreement with the carrier. That case, like the case now before us, involved claims for compensation which could only be adjudicated by a determination of the relevant facts and construction of the collective bargaining agreement. However, here, as was not the case in Order of Railway Conductors, the claimant has retired from railroad service. The immediate question is whether that factual difference makes a legal difference.
  . The Act grants jurisdiction to the Board of “disputes between an employee . . . and a carrier . . . .” It defines “employee” as including:
  “. . . every person in the service of a carrier (subject to its continuing authority to supervise and direct the manner of rendition of his service) who performs any work defined as that of an employee or subordinate official in the orders of the Interstate Commerce Commission ....’’
  The National Railroad . Adjustment Board was established as a tribunal to settle disputes arising out of the relationship between carrier, and employee. All the considerations which led Congress to entrust an expert administrative board with the interpretation of collective bargaining agreements are equally applicable when, as here, the employee has retired from service after initiating a claim for compensation for work performed while on active duty. The nature of the problem and the need for experience and expert knowledge remain the same. The same collective bargaining agreement must be construed with the same need for uniformity of interpretation and orderly adjustment of differences. There is nothing in the Act which requires that the employment relationship subsist throughout the entire process of administrative settlement. The purpose of the Act is fulfilled if the claim itself arises out of the employment relationship which Congress regulated. The Board itself has accepted this construction and adjudicates the claims of retired employees.. This uniform administrative interpretation is of great importance, reflecting, as it does, the needs and fair expectations, of the railroad industry for which Congress has provided what might be termed a charter for its internal government. Moreover, the discharged employee may challenge the validity of his discharge before the Board, seeking reinstatement and bacjk pay. See Union Pacific R. Co. v. Price, post, p. 601. Thus it is plain both from a reading of the Act in light of its purpose and the needs of its administration and from the settled administrative interpretation that the Board has jurisdiction over respondent’s claim for compensation.
  Since the Board has jurisdiction, it must have exclusive primary jurisdiction. All the considerations of legislative meaning and policy which have compelled the conclusion that an active employee must submit his claims to the Board, and may not resort to the courts in the first instance, are the same when the employee has -,retired and seeks compensation for work performed while he remained on active service. A contrary conclusion yvould create a not insubstantial class of preferred claimants. Retired employees would be allowed to bypass the Board specially constituted for hearing railroad disputes whenever they deemed it advantageous to do so, whereas all other employees would be required to present their claims to the Board. This case forcefully illustrates the difficulties of such a construction. Several active workers have had claims similar to that of respondent rejected by the Board. To allow respondent now to try his claim in the District Court would only accentuate the danger of inequality of treatment and its consequent discontent which it was the aim of the Railway Labor Act to eliminate. We can take judicial notice of the fact that provisions in railroad collective bargaining agreements are of a specialized technical nature calling for specialized technical knowledge in ascertaining their meaning and application. Wholly apart from the adaptability of judges and juries to make such determinations, varying jury verdicts would imbed into such judgments varying constructions not subject to review to secure uniformity. Not only would this engender diversity of proceedings but diversity through judicial construction and through the construction of the Adjustment Board. Since nothing is a greater spur to conflicts, and eventually conflicts resulting in strikes, than different pay for the same work or unfair differentials, not to respect the centralized determination of these questions through the Adjustment Board would hamper if not defeat the central purpose of the Railway Labor Act.
  Our decision in Moore v. Illinois Central R. Co., 312 U. S. 630, does not stand in the way of this. The decision in that case has been given its proper, limited scope in Slocum v. Delaware, L. & W. R. Co., 339 U. S. 239. Moore carved out from the controlling doctrine of primary jurisdiction the unusual and special situation of wrongful discharge where the aggrieved employee had been expelled from the employment relationship. Moreover, since the discharge had been accepted as final by the employee, it is probable that the damages accrued primarily after the employment relationship had terminated.
  Our consistent regard for the importance of having disputes between railroad employees and carriers settled by the administrative Board which Congress established for that purpose requires respondent to resort to the NRAB for adjudication of his claim.
  The judgment is reversed, and the cause remanded, in order that the case niay be returned to the District Court, with instructions to dismiss the complaint for lack of jurisdiction.
  Reversed and remanded.
  See, e. g., Railroad Trainmen v. Chicago River & Ind. R. Co., 353 U. S. 30; Slocum v. Delaware, L. & W. R. Co., 339 U. S. 239; Order of Railway Conductors v. Pitney, 326 U. S. 561; Elgin, J. & E. R. Co. v. Burley, 325 U. S. 711.
  E. g., National Railroad Adjustment Board, First Division, Award No. 15406,; id., Awards Nos. 11888 (with interpretation of this award contained in Volume 81 of awards), 12418, 16129.
  In the year 1956-1957 there were 361,000 retired railroad employees receiving benefits under the Railroad Retirement Act. H. R. Doc. No. 278, 85th Cong., 2d Sess.
  The inapplicability of United States v. Interstate Commerce Comm’n, 337 U. S. 426, to the problem of this case, like its inapplicability to the problem in Union Pacific R. Co. v. Price, post, p. 601, decided today, is dealt with in the Court’s opinion in that case.
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