380 U.S. 460 (1965)
On February 6, 1963, petitioner, a citizen of Ohio, filed her complaint in the District Court for the District of Massachusetts, claiming damages in excess of $10,000 for personal injuries resulting from an automobile accident in South Carolina, allegedly caused by the negligence of one Louise Plumer Osgood, a Massachusetts citizen deceased at the time of the filing of the complaint.1 Respondent, Mrs. Osgood's executor and also a Massachusetts citizen, was named as defendant.2
On February 8, service was made by leaving copies of the summons and the complaint with respondent's wife at his residence, concededly in compliance with Rule 4 (d) (1).3 Respondent filed his answer on February 26, alleging, inter alia, that the action could not be maintained because it had been brought contrary to and in violation of the provisions of Massachusetts General Laws Chapter 197, Section 9.4
On October 17, 1963, the District Court granted respondent's motion for summary judgment.5 On appeal, the Court of Appeals for the First Circuit affirmed.6 The Supreme Court granted certiorari because of the threat to the goal of uniformity of federal procedure posed by the decision below.7
Whether, in a civil action where the jurisdiction of the United States district court is based upon diversity of citizenship between the parties, service of process shall be made in the manner prescribed by state law or that set forth in Rule 4 (d) (1) of the Federal Rules of Civil Procedure?8
The Rules Enabling Act, 28 U.S.C. § 2072, empowers the Supreme Court to prescribe rules of practice and procedure for the district courts provided the rules do not abridge, enlarge, or modify substantive rights.9 When a Federal Rule of Civil Procedure is in direct conflict with a state rule, the Federal Rule governs if it is valid under the Enabling Act and the Constitution.10 The Erie doctrine does not displace properly adopted Federal Rules.11
Yes.
On February 6, 1963, petitioner Hanna, an Ohio citizen, filed her complaint in the District Court for the District of Massachusetts against respondent Plumer, the Massachusetts executor of Louise Plumer Osgood, seeking more than $10,000 in damages for injuries from a South Carolina automobile accident allegedly caused by Osgood's negligence. Two days later, on February 8, service was made by leaving copies of the summons and complaint with the respondent's wife at his residence, satisfying Rule 4(d)(1) but not Massachusetts General Laws Chapter 197, Section 9, which requires in-hand service or probate-registry notice within one year of the executor's bond.
Respondent answered on February 26 alleging violation of the state statute. The District Court granted summary judgment on October 17, 1963, and the Court of Appeals affirmed, treating the service requirement as substantive under Erie and its progeny. The Supreme Court granted certiorari to resolve the conflict between the federal rule and state law.
Rule 4(d)(1) regulates the manner of notifying a defendant that suit has been filed and therefore falls within the practice and procedure governed by the Enabling Act.12 Service here complied with the federal rule by leaving copies with a person of suitable age and discretion at the dwelling.13 The Massachusetts in-hand requirement directly conflicts with the federal rule.14 Yet the federal rule controls because it was validly promulgated.15 The difference in notification methods is not substantial enough to implicate Erie's twin aims of discouraging forum shopping and avoiding inequitable administration of the laws.16
Rule 4(d)(1) governs service of process in this diversity action and the judgment of the Court of Appeals is reversed.17
Related opinions on this issue
Justice Harlan concurred in the judgment.18 He viewed Erie as resting on constitutional allocation of law-making power between state and federal systems, requiring state law to prevail when it governs primary private activity and would be substantially affected by a federal rule.19 Harlan proposed testing whether the choice of rule would substantially affect primary decisions respecting human conduct left to the states.20
Applying that standard, he concluded that substituting Rule 4(d)(1) would require an executor only to check his residence or the federal courthouse in addition to the probate registry before distributing assets, producing no substantial effect on the speed or assurance of estate distribution and therefore leaving the state policy unimpinged.21