Back in the 90's there used to be a huge deal about receiving separation pay once you reach your RCP. That program has been discontinued due to the amount of sub-par soldiers who avoided promotions so that they may receive these lump sum payments.
The new RCP program can be found in AR 601-280. Here is an blurp of the reg:
(1) A soldier may not exceed the retention control points as shown below, by more than 29 days before expiration of contracted service (reenlistment or extension), see table 3-1 below.
Table 3–1
Retention control points
Rank Total active service in years
PVT-PFC 3
CPL/SPC 10
CPL/SPC (Promotable) 15
SGT 15
SGT (Promotable) 20
SSG 22
SSG (Promotable) 24
SFC 24
SFC (Promotable) 26
1SG/MSG 26
1SG/MSG (Promotable) 30
CSM/SGM 30
Notes:
1 The RCP for soldiers in the ranks of SSG(P) and above who are assigned to special bands (West Point Band, The Army Band, The Fife and Drum Corps and the Army Field Band) differs from the above table. They are: SSG(P) and SFC 30 years; SFC(P) and 1SG/MSG 33 years; and 1SG/MSG(P) and CSM/SGM 35 years.
2 Command sergeants major serving in nominative positions when the commander is a GO are authorized retention beyond 30 years. These soldiers will not be retained beyond 35 years of total active service.
(2) Except for soldiers serving indefinite reenlistments, soldiers who reach their RCP during their current enlistment agreement, either through length of service, reduction in rank, or by removal from a promotion list, whether voluntary or involuntary, may serve until contracted Expiration Term of Service (ETS), unless they are separated earlier under
applicable administrative, physical disability, or UCMJ separation provisions. Soldiers in this category who are eligible may apply for retirement. Soldiers with less than 18 years AFS serving indefinite reenlistments who exceed RCP as the result of a reduction in rank may serve to minimum retirement eligibility unless they are separated earlier under applicable administrative, physical disability, or UCMJ separation provisions.
(3) As an exception, Soldiers in the rank of PFC or below:
(a) Who are in the rank of PFC on their initial enlistment of 3 or less years, if otherwise qualified, to include those
with approved waivers, and reenlist prior to 26 months total active service, are eligible to reenlist for a period not to
exceed 6 years 29 days.
(b) Who are eligible for a SRB and in the rank of PFC on their initial enlistment of less than 4 years, (such as, original enlistment of 2 years and 26 weeks) if otherwise qualified, to include 21 months continuous Active Federal
Service (other that ADT), and those with approved waivers, are eligible to reenlist for a period not to exceed 5 years to become eligible to receive an SRB. Total active service will not exceed 7 years and 29 days.
(c) Who incur a DA imposed service remaining requirement, if otherwise qualified to include those with approved waivers, are eligible for extension/reenlistment. The extension will only be for the time necessary to fulfill the service
remaining requirement. Total active service will not exceed 7 years 29 days. Prior service soldiers may exceed 7 years 29 days. These soldiers are permitted to reenlist for the time necessary to fulfill the service remaining requirement, not to exceed the RCP for the next higher rank.(d) Who are reduced in rank are not authorized reenlistment or extension under (a) (b) or (c) above.
(4) Rank eligibility does not apply to soldiers selected for attendance at an officer training program (that is, Officer Candidate School or Warrant Officer Flight Training).
h. Marital status and number of dependents. A soldier’s marital status and number of dependents is immaterial.
Hope that helps

Be prepared for the worst and hope for the best.